The image shows the notification service interfaces and supported service types and where each fits in the two tiers from left to right. A) The tier on the left shows a BPEL process with an outbound arrow labeled Web Services Interface (WSIF binding) and a Human workflow task desktop computer with an outbound arrow labeled Java Interface. Both outbound arrows connect to an Oracle User Messaging Service label on the right. The Oracle User Messaging Service has four arrows connecting to it from the right: Email Server, SMS Server, Voice Gateway, and IM Server. On the left side of the Oracle User Messaging Service is an outbound arrow labeled Java Call. This arrow connects to the BPEL process and Human workflow task on the left.